# how come Photons are deemed to be mass less when the equation for its energy contains mass=E= Mass x C^2?

### 5 Answers

- skeptikLv 73 months agoFavorite Answer
Ummmmmmm ...

Where did you get the idea that equation says something with energy must also have mass?

- CarolOklaLv 73 months ago
Wrong equation. E = hv where

E= energy

h = Planck constant, which really is "constant"

v = frequency, NOT velocity.

The speed of light IS NOT "CONSTANT"!!!!!

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goring, your perfect square wave has an infinite acceleration unless the amplitude of your infinite frequency is zero. So does a wave of infinite frequency with zero amplitude represent a real wave? But what has that to do with the question?

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- 3 months ago
E = mc^2 only applies to an object at rest. Photons are never at rest. The full equation is

E^2 = (mc^2)^2 + (pc)^2

The energy of a photon is also given by E = hf where f is its frequency and h is planks constant.

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Energy is just a transfer function between Power and time= no time no energy

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- Anonymous3 months ago
E= Mass x C^2 is only for stationary objects.

In general

E^2 = (Mass x C^2)2 + (Momentum x C)^2

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- SlumlordLv 73 months ago
They are energy, this equations tell you what their mass would be if they wre converted to mass.

precipitation of energy into mass cannot occur in the physical universe because a mass in motion is said to have energy.No mass exist without motion.

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you missed the whole point about frequency meaning in Power = hf